1. Field of the Invention
The present invention relate to a turn signal cancel device which automatically rotates and returns an operation lever, which has been operated to indicate the turn direction of a vehicle, to its neutral position.
2. Related Art
Description will be given below of a conventional structure of a turn signal cancel device of this type with reference to FIG. 11. That is, a bracket 2 is mounted to a body 1 in such a manner that it can be rotated about a shaft 2a, and an operation lever 3 and a back plate 4 are respectively mounted to the bracket 2. Also, a ball 5 is mounted on the bracket 2 and the ball 5 is in engagement with an uneven surface 1a formed in the body 1. According to this structure, the operation portion side of the operation lever 3 can be selectively held at a horizontal neutral position, a downwardly inclined right turn direction position, and an upwardly inclined left turn direction position. FIG. 11 illustrates a state in which the bracket 2 is held at the right turn direction position.
Also, a ratchet 6 is rotatably mounted to the body 1. While the bracket 2 is held at the right turn direction position, if a steering wheel (not shown) is turned, a cancel cam 7 is rotated in a direction of an arrow A shown in FIG. 11 into engagement with the leading end portion of the ratchet 6 to thereby rotate the ratchet 6 in a direction of an arrow B shown in FIG. 11. This causes a pressure portion 6a, which is located on the base end portion side of the ratchet 6, to press against a projected portion 4a provided in the back plate 4, so that the ratchet 2 is rotated and returned to its neutral position. In this structure, the pressure portion 6a of the ratchet 6 is rotated from its state that it is in surface contact with the projected portion 4a of the back plate 4. Therefore, the projected portion 4a of the back plate 4 is given a pressure by the end portion 6b of the pressure portion 6a of the ratchet 6 as well.
The end portion 6b of the pressure portion 6a is rotated at a high speed. That is, when the steering wheel is turned at a high speed, then the end portion 6b is rotated at a high speed. Therefore, in the conventional structure in which the back plate 4 is pressed by the end portion 6b rotating at a high speed, the fast turn of the steering wheel is easy to reflect on the rotational operation of the bracket 2.
In order to prevent this, a modification can be imagined. That is, as shown by a two-dot chained line in FIG. 11, the leading end portion of the ratchet 6 is cut out to form an inclined portion 6c, thereby reducing the engaging margin of the cancel cam 7 with the ratchet 6. This modification can reduce the quantity of rotation of the bracket 2, thereby preventing the fast turn of the steering wheel from reflecting on the rotational operation of the bracket 2. However, in this modification, there is produced a possibility that the turn of the steering wheel does not reflect on the rotational operation of the bracket 2.